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Biomedical subjects

B E Roberts

Publications and source records attributed to B E Roberts.

14 recordsLinked to original sources
PubMed1979

Purification and mapping of specific mRNAs by hybridization-selection and cell-free translation.

We describe a simple procedure for isolating specific mRNAs and for mapping them to the regions of the DNA from which they originate. The method involves hybridization of total cytoplasmic RNA to restriction fragments of DNA that have been fractionated in agarose gels and immobilized on nitrocellulose filters. The hybridization-selected RNAs are eluted and translated in a cell-free system in order to identify their encoded polypeptides. Optimal hybridization and filter washing conditions are given for selection of mRNAs from adenovirus 2-infected cells and transformed cells.

Adenoviridae↗
PubMed1979

The 3' noncoding region of beta-globin mRNA is not essential for in vitro translation.

Rabbit beta globin DNA sequence, excised from plasmid pbetaG1, directs in vitro synthesis of beta-globin in a transcription-translation cell-free system, even after specific elimination of the entire 3'-noncoding region. A DNA restriction fragment carrying this 3' noncoding region and hybridized to globin mRNA cannot arrest the cell-free translation of beta-globin mRNA.

Animals↗
PubMed1978

Morphological and immunological similarity of the monocytes from pure and mixed monocytic leukaemias.

Morphological and immunological marker data on a patient with 'pure' monocytic leukaemia are presented and compared with those of 6 cases of clearly mixed myelomonocytic leukaemia with a variable monocytic component. In all patients studied, the leukaemic monocytes expressed a receptor for the Fc of IgG, and IgG sensitization markedly enhanced phagocytosis of ox erythrocytes. A variable, but lower, percentage of the leukaemic monocytes had a receptor for mouse C3, but the cells uniformly lacked surface immunoglobulin and receptors for the Fc of IgM and for unsensitised mouse erythrocytes. Cytochemical and ultrastructural study also showed no clear difference between the monocytes of the 'pure' and mixed monocytic leukaemias. This report therefore lends no support to the concept of distinct types of monocytic leukaemia.

Binding Sites, Antibody↗
PubMed1978

Evaluation of the usefulness of serum gamma-glutamyl transpeptidase levels in the management of haematological neoplasia.

The levels of serum gamma-glutamyl transpeptidase (GGT) and, when appropriate, alkaline phosphatase (AP) and 5'-nucleotidase (NTD) have been measured as a routine in 276 patients with malignant haematological diseases during a 26-month trial period. GGT levels add no prognostic information to the routine haematological surveillance of leukaemia. Polychemotherapy does not appear to be an inducer of liver drug-metabolising microsomal enzymes. Polycythaemia rubra vera, myelofibrosis and chronic lymphocytic leukaemia may cause little change in GGT, AP and NTD levels despite marked hepatomegaly. A raised GGT in Hodgkin's disease and non-Hodgkin lymphoma is generally associated with active and widespread disease, but not necessarily a sign of malignant tissue in the liver. The elevations of GGT in myeloma may be secondary to liver infiltration though this group merits further detailed study.

Hodgkin Disease↗
PubMed1978

Hairy-cell leukemia with T-cell features.

A case of clinically and hematologically typical hairy-cell leukemia has been presented in which, at the various times of testing, 52%-95% of peripheral blood and 73% of splenic mononuclear cells formed spontaneous sheep erythrocyte (E) rosettes. Many of the rosetting cells were shown to be typical morphologic hairy cells by light and electron microscopy. It was found that 70%-75% of peripheral blood mononuclear cells stained with an anti-T antiserum, and this antiserum also abolished E-rosette formation. A variable percentage of peripheral blood mononuclear cells was also shown to bear surface (IgDK) and internal (IgMK and IgGK) immunoglobulins. Additional B-cell features demonstrated included possession of the P29/34 la-like antigen and formation of mouse rosettes. It was demonstrated by a variety of blocking and inhibition studies that the E-rosette formation was not attributable to chance antigen specificity of the surface membrane immunoglobulin. These marker studies suggest that this is a case of true hybrid cell HCL. Despite these unusual marker characteristics, the patient showed no distinctive clinical or hematologic features.

Animals↗
PubMed1977

DNA complementary to parathyroid mRNA directs synthesis of pre-proparathyroid hormone in a linked transcription-translation system.

DNA complementary in sequence to the messenger RNA for pre-proparathyroid hormone was synthesised using reverse transcriptase. In a linked transcription-translation system using RNA polymerase and cell-free extract from wheat germ, the DNA directed the synthesis of a protein identified as pre-proparathyroid hormone by N-terminal sequencing and by electrophoretic and immunologic criteria.

Amino Acid Sequence↗
PubMed1977

Pleomorphic B cell neoplasm with monoclonal IgA secretion: a case report.

A case of non-myelomatous malignant disease with IgA paraproteinemia is described. A pleomorphic lymphoid/plasmacytoid infiltrate was found in the bone marrow. While the cells studied had some ultrastructural characteristics closer to myelomatosis than Waldenström's macroglobulinemia, immunofluorescence showed IgA in both the cytoplasm and at the cell surface, as seen with IgM in macroglobulinemia but not with IgA in typical IgA myelomatosis. This case illustrates that IgA paraproteinemia may be produced in association with pleomorphic B cell proliferative diseases as well as myelomatosis. There is probably a spectrum of disease states as with IgM paraproteinemia.

Adult↗
PubMed1977

Structural gene identification and mapping by DNA-mRNA hybrid-arrested cell-free translation.

We present a simple method for directly correlating structural gene sequences in DNA with their corresponding mRNAs. This is based upon the fact that mRNA hybridized with its complementary DNA will not direct the cell-free synthesis of a complete polypeptide. Full translational activity of the mRNA is recovered upon the heat melting of the hybrid. Utilizing the rabbit beta globin clone PbetaG1, we demonstrate the application of hybrid-arrested translation for the identification of structural gene sequences within recombinant DNA molecules. In addition, the method is used to locate and order precisely several adenovirus 2 polypeptides within the viral genome.

Animals↗
PubMed1977

Surface marker and other characteristics of Gaucher's cells.

A full surface marker study of the splenic storage cells in a case of Gaucher's disease largely substantiates the monocyte/histiocyte nature of Gaucher's cells. In addition, an apparent T-lymphocyte deficiency is demonstrated in the spleen and peripheral blood, and the possible significance of this finding is discussed.

Cell Extracts↗
PubMed1977

Acute phase reactant proteins in chronic leukaemia.

The levels of haptoglobin, alpha1 antitrypsin and alpha1 acid glycoprotein are moderately raised in chronic leukaemias. In CGL the level of haptoglobin and acid glycoprotein show the highest correlation with cell number, whilst no such correlations occur in CLL or CMML. There does not appear to be a relation between blood lysozyme levels and the levels of antiprotease (alpha1 antitrypsin and alpha2 macroglobulin).

Chronic Disease↗
PubMed1976

Direct biochemical mapping of eukaryotic viral DNA by means of a linked transcription-translation cell-free system.

A method is described for mapping regions of eukaryotic viral DNA coding for specific proteins, utilizing a linked transcription-translation cell-free system primed with DNA fragments generated by restriction endonucleases. Three simian virus 40 (SV40) DNA fragments derived from that region of the DNA expressed late in lytic infection were purified. They were: Hpa I-A (0.76-0.175 map units), Bgl I-EcoRI-B (0.672-0), and Hpa II-EcoRI-B (0.735-0). (Fragments are named from the cleaving restriction endonuclease and electrophoretic mobility. End positions on the conventional map are in clockwise order.) These fragments efficiently stimulated the incorporation of [3H]UTP and [35S]methionine into trichloroacetic-acid-insoluble material in the linkec system. The location of the region of DNA coding for the viral structural proteins VPI, VP2 and VP3 was determined from the spectrum of polypeptide synthesis directed by the individual intact fragments and their specific endonucleolytic digests. The polypeptides synthesized in the cell-free system were characterized on urea-sodium dodecyl sulfate polyacrylamide gradient gels and by two-dimensional tryptic peptide analysis. ..

Cell-Free System↗
PubMed1975

Simian virus 40 DNA directs synthesis of authentic viral polypeptides in a linked transcription-translation cell-free system.

A linked cell-free system has been developed which is capable of transcribing and translating mamalian viral DNA, and its characteristics and requirements are outlined. In this system, simian virus 40 (SV40) DNA Form I (supercoiled) directed the synthesis of discrete polypeptides up to 85,000 daltons in size. One of these products was indistingusihable from authentic major virus capsid protein VPI, as judged by mobility on sodium dodecyl sulfate/polyacrylamide gels, antibody predipitation, and peptide analyses. The cell-free products larger than VPI comprised a number of polypeptides ranging in molecular weight from 50,000 to 85,000. These polypeptides demonstrated no immunological relationship whatsoever to the structural protein VPI. However, two of these products, along with one of approximately 25,000 dlatons, were precipitated with antiserum to SV40 tumor antigen. Linear SV40 DNA generated by the cleavage of Form I DNA with the restriction endonuclease EcoR1 was an efficient template in this system and also directed the synthesis of a polypeptide migrating with VPI on polyacrylamide gels. The potential of this system for defining a functional map of a DNA genome is discussed.

Animals↗